1. Technical Field
The present invention relates to a projector.
2. Related Art
Projectors using a laser source have an advantage that miniaturization of the device can be achieved, an advantage of being superior in color reproducibility, and advantage that instantaneous lighting can be performed, an advantage that the life of the light source is long, and other advantages. Incidentally, the laser beam emitted from the laser source is generally a coherent light beam. Therefore, in the projectors of this kind, there are some cases in which a speckled pattern caused by interference of the laser beams, a so-called speckle, is visually recognized on a screen. This significantly degrades the display quality.
In the projector using a laser source, there are taken measures for suppressing the degradation of the display quality due to the speckle. In JP-A-2011-180281 (Document 1), there is disclosed a projection video display device equipped with an equalizing optical element (a diffusing optical element), which equalizes the spatial distribution of the light intensity in the exit pupil of a projection optical system, and is disposed between a light source and a light modulation element.
Although the projection video display device of Document 1 is equipped with the equalizing optical element, the effect for reducing the speckles obtained by merely providing the equalizing optical element is still insufficient.